Air-assisted fiber installation, or blowing, is a technique for installing an optical fiber in a duct that offers an alternative to the conventional technique of threading a line through the duct, attaching the line to the fiber, and pulling or tugging the fiber through the duct. As the fiber is fed into the duct from a mechanical drive through an inlet guide, a high-pressure, high-volume air flow is introduced into the duct to push the fiber through the duct.
One known implementation of the inlet guide is a hydroscopic needle. However, the needles located at the inlet end are exposed to the mechanical drive and thus easily damaged. Also, the needles are susceptible to becoming filled with dirt, excess material, and/or other foreign substances which can clog the pathway and inhibit proper dispensation of the optical fibers therefrom.
FIGS. 1A and 1B illustrate a conventional inlet guide 100 that includes a cylindrical housing 102 having openings 104 at one end to receive fibers (not shown) and guides 106 at the other end for guiding the fibers into associated ducts (not shown). FIG. 1A is a rear perspective view depicting a conventional inlet guide. FIG. 1B is a front perspective view of the conventional inlet guide of FIG. 1A. The inlet guide 100 also has a flange 108 that defines a plurality of screw holes 110. The inlet guide 100 is attached to a housing of a feeding unit (not shown) with four screws (not shown) that are inserted through the screw holes 110. That particular arrangement accommodates between eight to twelve fibers and uses a point-over-point entry configuration which can cause cross-over issues with the fibers entering the inlet guide 100 and can also cause friction thereby damaging the fibers during installation.